The quad-rotor (or quad copter) is a complex system that has lately submerged the aerospace field. In this article, components are chosen from Modelica's different block libraries to build the multi-body model. On this model, simplified dynamic equations are implemented according to a certain disposing configuration. Based on disk actuator theory, a multi-disciplinary optimization takes place in order to improve some system characteristics such as power, weight throughout a link between ModelCenter and Catia V5 and with a focus only on the propeller.